Minimize Browse Data Products
Earth Topics (Applications)
  • Land
  • Topography/Mapping

  • Snow and Ice
  • Sea Ice

  • Ocean and Coast
  • Ocean Currents and Topography

  • Solid Earth
  • Geoid

  • Atmosphere
  • Winds

    Instrument type
  • RA
  • Mission
    Date of Launch:
    ERS-1 - 17 July 1991
    ERS-2 - 21 April 1995
    Mission Status:
    ERS-1 ended on March 2000 and ERS-2 September 2011 
    Orbit Height:
    782 to 785 km
    Orbit type:
    Near-circular, polar, Sun-synchronous
    Swath Width:
    5 km
    Radar Altimeter REAPER Geophysical Data Record - GDR
    (2159) recent views
    Last update: 10 September 2014

    This is a RA Geophysical Data Record (GDR) product containing radar range, orbital altitude, wind speed, wave height and water vapour from the ATSR/MWR as well as geophysical corrections.

    The REAPER (REprocessing of Altimeter Products for ERS) product is generated by applying a similar processing as for Envisat RA-2 on the Level 1b consolidated waveforms using 4 different re-trackers, RA calibration improvement, new precise orbit solution (POD), new ionospheric corrections (NICO09 until 1998 and GIM up to 2003), ECMWF ERA-interim model and updated SSB tables.

    This product contains two data rates: a low rate of 1Hz and a high rate of 20Hz.

    Most 1Hz data is also represented at 20Hz, while microwave radiometer (ATSR/MWR) data and the atmospheric and geophysical corrections are only given at 1 Hz.

    The REAPER GDR (ERS_ALT_2_) is a global product including data over ocean, ice and land.

    It should be noted that this product differs from the Envisat RA2 in the following ways:

    • the product format; which is NetCDF (more details can be found in the Product Handbook), and not PDS
    • the product is delivered based on orbit acquisition and not per pass (pole-to-pole)
    Data Set Specifications
    Spatial coverage: 90 N, 90 S, 180 W, 180 E
    Processing level
    Level 2
    How to access this data

    Data is distributed via FTP upon registration.

    REAPER ERS-1 data is available from 3 August 1991 to 2 June 1996

    REAPER ERS-2 data is available from 15 May 1995 to 4 July 2003

    This product is extended through Envisat RA-2 data

    See also related news of 11 September 2014.

    Terms & Conditions applicable
    Utilisation of this data is subject to ESA's Earth Observation Terms and Conditions


    REAPER Data Product Handbook


    REAPER Calibration Monitoring


    Cal/Val evaluation of REAPER ERS altimeter data


    RA L2 Validation Report


    REAPER Data Performance Monitoring and QA


    More RA Documents

    Minimize From Delivery to Acquisition
    Minimize ESA Earth Observation Campaigns Data

    ESA has been involved in many Earth Observation campaigns over the past 25 years, from ground-based surveys, to ships at sea, aircraft and balloons in the atmosphere and the orbiting satellites in space.

    To learn more about these campaigns and available datasets from them, please see the Campaigns page.